Color radiography



Oct 30, 1962 G. s. MITTELSTAEDT 3,061,722

COLOR RADIOGRAPHY Filed March 7, 1960 1-9 F I G 2 )GREEN F l G 5 INVENTOR.

United States Patent [Ofiice 3,061,722 Patented Oct. 30, 1962 3,051,722 COLOR RADIOGRAPHY Georg S. Mittelstaedt, 274 73rd St., Brooklyn, N.Y. Filed Mar. 7, 1960, Ser. No. 13,085 13 Claims. (Ci. 250-65) This invention relates to radiography, and it relates particularly to opaque screens in connection with amplified X-rays and light sensitive emulsions.

In the text and claims, by opaque is meant not allowing visible light to pass through, but allowing all intensities of X-rays to pass through.

In the text and claims, by the term penetrating radiation is meant X-rays, alpha, beta, gamma rays, neutrons etc., and by emulsion is meant light sensitive layer.

It is an object of this invention to stop visible light between light sensitive layers, but allowing all intensities of X-rays to pass through.

Another object is to produce a density analysis.

Still another object is to produce radiographs in contrasting color.

The above and other objects will become apparent in the description below, in which characters of reference refer to like-named parts in the drawing.

' The drawing shows in diagrammatic greatly enlarged form light sensitive layers, used in association with screens which are opaque to visible light but allow all intensities of X-rays to pass through and in association with intensifying screens, all shown in section.

FIGURE 1 shows light sensitive layers in association with the defined opaque screens.

FIGURE 2 shows the device with the addition of intensifying screens.

FIGURE 3 shows the device expressly applied to color radiography.

In all figures, the numerals l, 2 and 3 indicate emulsion layers, the numerals 4 and 5 indicate the defined opaque screens, and the numerals 6, 7 and 8 indicate amplifying foils.

The numeral 9 shows the direction of the penetrating radiation.

Referring in detail to the drawing, in FIGURE 1 the numerals 1, 2 and 3 indicate emulsion layers, each containing X-ray intensifying substance of difierent sensitivity, and successive layers react to different intensities of X-rays. These emulsion layers may also be color sensitive, preferably each layer producing a different color, and the fluorescent substance respectively allotted to the individual emulsion layer is preferably adapted to produce a colored light which is predominately of the same color as that to which the respective emulsion layer is sensitized. The numerals 4 and 5 indicate screens which are opaque to visible light, but allow all intensities of X-rays to pass through. Since different emulsion layers react to diiferent intensities of X-rays, a density analysis is produced.

In FIGURE 2, the numerals 1, 2 and 3 indicate emulsion layers. The numerals 6, 7, and 8 indicate separate amplification foils disposed adjacent to separate emulsion layers. The foil 6 combines with emulsion layer 1, the foil 7 with emulsion layer 2, and the amplification foil 8 combines with emulsion layer 3. Successive amplification foils contain fluorescent substance of different sensitivity, and successive foils respond to difierent intensities of X-rays. The amplification foil and emulsion layer combinations are separated with screens 4 and 5, which are opaque to visible light, but allow all intensities of X-rays to pass through. Since different amplification foils respond to difierent intensities of X-rays, a density analysis is produced.

The preferred example illustrated in FIGURE 3 is similar to FIGURE 2, but successive emulsion layers are sensitized to different colors, and successive amplification foils are adapted to produce different color lights. Here, the numeral 1 indicates a blue sensitive emulsion layer, and 6 a blue emitting amplification foil. The numeral 2 indicates a green sensitive emulsion layer, and 7 a green light emitting foil. The numeral 3 indicates a red sensitized emulsion layer, and 8 indicates a red light emitting amplification foil. Successive amplification foils contain fluorescent substance of different sensitivity, and successive foils respond to different intensities of X-rays. The amplification foil and emulsion layer combinations are separated with screens 4 and 5, which are opaque to visible light, but allow all intensities of X-rays to pass through. Since different amplification foils respond to different intensities of X-rays, a density analysis in contrasting colors is produced.

It is known that phosphors may be made selectively responsive to radiation intensity.

Since phosphors may be made to respond to different intensities of X-rays, successive amplification foils can be made selectively responsive to radiation intensity. This can be done by varying the mean particle size of the fluorescent crystals in successive foils, or there may be used different mixtures of large and small crystals in successive foils, or the content of fluorescent substance may vary in different foils, or any other of the many known means may be employed to vary the response to radiation intensity in successive amplification foils.

Therefore, weak intensities of X-rays excite the phosphor having the highest sensitivity, the middle intensities excite the phosphors having high or intermediate sensitivity, and the high intensities of radiation affect all phosphors, causing light emission from them all. In other words, the most responsive phosphor is excited by all intensities of X-rays, including the lowest, the medium phosphor is excited by medium and high intensities of X-rays only, and the least responsive phosphor is excited only by the high intensities of X-rays.

It is old in the art to make amplification foils which produce different color lights, difierent foils producing different colors.

In this invention, all emulsion layers are usually exposed at one time, but emulsion layers may be individually exposed in combination with selectively sensitized amplifying means.

Exposed photographic emulsion layers are developed, and the density analysis or part thereof may be combined.

The density analysis illustrated in FIGURE 2, in which the emulsions are not color sensitized, or part thereof, may be dyed in contrasting colors and may be combined, or the analytical density records may be projected through filters of contrasting color and may be combined, to form a radiograph in contrasting colors. But the synthesis of the photographic analysis may take any of the many different physical and chemical forms, depending on whether the synthesis is to be additive or subtractive and on the method of image formation.

It is part of this invention to coat an emulsion layer with opaque substance and/or with fluorescent substance, and in the claims, by screen or foil is also meant coat or layer. Such coated substances may be re moved after exposure, preferably during the developing process.

It is to be noted that the principles involved in his invention may be applied to all fields of radiography.

Physical and chemical changes may be made within the spirit and scope of this invention.

I claim:

1. In combination with a radiographic arrangement comprising a source of penetrating radiation and a plurality of successively disposed photographic emulsion layers subjected to penetrating rays emanating from said source, fluorescent substances of different sensitivity dispersed in successive emulsion layers.

2. In an arrangement according to claim 1, fluorescent substances of different color light emission dispersed in successive emusion layers.

3. In an arrangement according to claim 1, fluorescent substances of different sensitivity and different color light emission dispersed in successive emulsion layers.

4. In combination with a radiographic arrangement comprising a source of penetrating radiation and a plurality of successively disposed photographic emulsion layers subjected to penetrating rays emanating from said source, fluorescent substances of different sensitivity coated on successive emulsion layers.

7 5. In an arrangement according to claim 4, fluorescent substances of different color light emission coated on successive emulsion layers.

6. In an arrangement according to claim 4, fluorescent substances of different sensitivity and different color light emission coated on successive emulsion layers.

7. In combination with a radiographic arrangement comprising a source of penetrating radiation, a plurality of successively disposed light sensitive layers subjected to penetrating rays emanating from said source of penetrating radiation, and visible light-opaque, penetrating radiation-transparent screens disposed between said light sensitive layers, effectively unequal intensifying screens disposed between successive light sensitive layers.

8. In an arrangement according to claim 7, effectively unequal intensifying screens. with different color light emission disposed between successive light sensitive layers.

9. In combination with an arrangement for producing in a single illumination operation, with penetrating rays emanating from a suitable source, a density analysis comprising a plurality of successively disposed light sensitive layers and a visible light-opaque, penetrating radiation-transparent screen disposed between said light sensitive layers, a selective intensifying screen adjacent one of said light sensitive layers, said intensifying screen responding only to a select intensity range of said penetrating radiation.

10. In combination with an arrangement for producing in a single illumination operation, with penetrating rays emanating from a suitable source, a density analysis comprising a plurality of successively disposed light sensitive layers and a visible light-opaque, penetrating radiation-transparent screen disposed between said light sensitive layers, intensifying screens of different sensitivity and light emission adjacent individual light sensitive layers, said intensifying screens responding to difierent intensities of penetrating radiation.

ll. In an arrangement according to claim 10, intensifying screens of different sensitivity and different color light emission adjacent individual light sensitive layers, said intensifying screens responding to different intensities of penetrating radiation.

12. In combination with an arrangement for produc ing in a single illumination operation, with penetrating rays emanating from a suitable source, a density analysis comprising a plurality of successively disposed light sensitive layers and visible light-opaque, penetrating radiationtransparent screens disposed therebetween, intensifying screens responding to different intensities of penetrating radiation disposed between said light sensitive layers, said intensifying screens producing different illumination in successive light sensitive layers, resulting in unequal exposure thereof.

13. In an arrangement according to claim 12, intensitying screens responding to different intensities of penetrating radiation and having difierent color light emission disposed between said light sensitive layers, said intensifying screens producing different illumination in successive light sensitive layers, resulting in unequal exposure thereof.

References Cited in the file of this patent UNITED STATES PATENTS 2,644,096 Pine June 30, 1953 2,807,725 Schwerin Sept. 24, 1957 2,844,732 Hartmann 2 July 22, 1958 2,906,331 Mittelstaedt Sept. 29, 1959 

